Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and...Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and have often been the focus of ecological and environmental research. This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period. The water body was extracted from MSS images from the mid-1970s, TM images from the early 1990s, ETM ＋ images in the late 1990s, and TM images in 2007. The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area, from 91402.06km^2 in 1975 to 46049.23 km^2 in 2007. As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part, the shrinking trend of lake area was more significant in the west than in the east. There was a varied reduction of closed lakes in flat regions. The most substantial decrease was in the surface area of closed lakes in flat regions. Most significantly, the area of the Aral Sea was reduced by 75.7% from its original area in 1975. The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007. The area change in opened lakes with outlets was notably different from the other two types. The area of Zaysan had increased sharply by 5.85%, and that of Bosten had decreased by 9.1%. Sasykkol had hardly any changes in this period. Due to global climate wanning, vapor transfer to the south via westerly winds had been blocked, resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan between 1970 and 2000. The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of fiver runoff. Consequently, thearea of inland lakes in Central Asia shrank over the past 32 years.展开更多
To achieve sustainable development,it is vitally important to identify the factors driving urban green innovation and evaluate the contributions of different factors.This study uses a Chinese patent full-text database...To achieve sustainable development,it is vitally important to identify the factors driving urban green innovation and evaluate the contributions of different factors.This study uses a Chinese patent full-text database from 2005 to 2016 to identify the number of green patents at the prefecture level and analyzes the main determinants that lead to differences in green innovation level in different regions and types,and their respective contributions by regression and decomposition.This study finds that first,China's green innovation level is characterized by unbalanced development among different regions-the coastal areas develop rapidly while the inland areas develop comparatively slowly.Green innovation output is polarized among different cities,and the trend is more severe in inland areas.Second,economic development acts as the leading factor influencing the overall green innovation output of China both in inland and coastal areas,factor input follows as the second influencing factor,while government behavior has a comparatively small impact on green innovation.Third,regarding green patents of different types in different regions,economic development still serves as the major factor of unbalanced output of all kinds of patents,and government behavior has a relatively obvious regional characteristic,whose impact on inland areas is more evident.展开更多
Inland lakes and alpine glaciers are important water resources on the Tibetan Plateau. Understanding their variation is crucial for accurate evaluation and prediction of changes in water supply and for retrieval and a...Inland lakes and alpine glaciers are important water resources on the Tibetan Plateau. Understanding their variation is crucial for accurate evaluation and prediction of changes in water supply and for retrieval and analysis of climatic information. Data from previous research on 35 alpine lakes on the Tibetan Plateau were used to investigate changes in lake water level and area. In terms of temporal changes, the area of the 35 alpine lakes could be divided into five groups: rising, falling-rising, rising-falling, fluctuating, and falling. In terms of spatial changes, the area of alpine lakes in the Himalayan Mountains, the Karakoram Mountains, and the Qaidam Basin tended to decrease; the area of lakes in the Naqu region and the Kunlun Mountains increased; and the area of lakes in the Hoh Xil region and Qilian Mountains fluctuated. Changes in lake water level and area were correlated with regional changes in climate. Reasons for changes in these lakes on the Tibetan Plateau were analyzed, including precipitation and evaporation from meteorological data, glacier meltwater from the Chinese glacier inventories. Several key problems, e.g. challenges of monitoring water balance, limitations to glacial area detection, uncertainties in detecting lake water-level variations and variable region boundaries of lake change types on the Tibetan Plateau were discussed. This research has most indicative significance to regional climate change.展开更多
文摘Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and have often been the focus of ecological and environmental research. This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period. The water body was extracted from MSS images from the mid-1970s, TM images from the early 1990s, ETM ＋ images in the late 1990s, and TM images in 2007. The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area, from 91402.06km^2 in 1975 to 46049.23 km^2 in 2007. As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part, the shrinking trend of lake area was more significant in the west than in the east. There was a varied reduction of closed lakes in flat regions. The most substantial decrease was in the surface area of closed lakes in flat regions. Most significantly, the area of the Aral Sea was reduced by 75.7% from its original area in 1975. The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007. The area change in opened lakes with outlets was notably different from the other two types. The area of Zaysan had increased sharply by 5.85%, and that of Bosten had decreased by 9.1%. Sasykkol had hardly any changes in this period. Due to global climate wanning, vapor transfer to the south via westerly winds had been blocked, resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan between 1970 and 2000. The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of fiver runoff. Consequently, thearea of inland lakes in Central Asia shrank over the past 32 years.
文摘To achieve sustainable development,it is vitally important to identify the factors driving urban green innovation and evaluate the contributions of different factors.This study uses a Chinese patent full-text database from 2005 to 2016 to identify the number of green patents at the prefecture level and analyzes the main determinants that lead to differences in green innovation level in different regions and types,and their respective contributions by regression and decomposition.This study finds that first,China's green innovation level is characterized by unbalanced development among different regions-the coastal areas develop rapidly while the inland areas develop comparatively slowly.Green innovation output is polarized among different cities,and the trend is more severe in inland areas.Second,economic development acts as the leading factor influencing the overall green innovation output of China both in inland and coastal areas,factor input follows as the second influencing factor,while government behavior has a comparatively small impact on green innovation.Third,regarding green patents of different types in different regions,economic development still serves as the major factor of unbalanced output of all kinds of patents,and government behavior has a relatively obvious regional characteristic,whose impact on inland areas is more evident.
基金The Major State Basic Research Development of China,No.2015CB954101National Mountain Flood Disaster Investigation Project,No.SHZH-IWHR-57+2 种基金The National Science and Technology Basic Special Project,No.2011FY11040-2National Natural Science Foundation of China,No.41171332The Surveying and Mapping Geoinformation Nonprofit Specific Project,No.201512033
文摘Inland lakes and alpine glaciers are important water resources on the Tibetan Plateau. Understanding their variation is crucial for accurate evaluation and prediction of changes in water supply and for retrieval and analysis of climatic information. Data from previous research on 35 alpine lakes on the Tibetan Plateau were used to investigate changes in lake water level and area. In terms of temporal changes, the area of the 35 alpine lakes could be divided into five groups: rising, falling-rising, rising-falling, fluctuating, and falling. In terms of spatial changes, the area of alpine lakes in the Himalayan Mountains, the Karakoram Mountains, and the Qaidam Basin tended to decrease; the area of lakes in the Naqu region and the Kunlun Mountains increased; and the area of lakes in the Hoh Xil region and Qilian Mountains fluctuated. Changes in lake water level and area were correlated with regional changes in climate. Reasons for changes in these lakes on the Tibetan Plateau were analyzed, including precipitation and evaporation from meteorological data, glacier meltwater from the Chinese glacier inventories. Several key problems, e.g. challenges of monitoring water balance, limitations to glacial area detection, uncertainties in detecting lake water-level variations and variable region boundaries of lake change types on the Tibetan Plateau were discussed. This research has most indicative significance to regional climate change.
